Transmission data for flight check

ABSTRACT

A method, system, and computer-readable medium for performing a flight check of one or more navigational aid systems. Aspects include obtaining, using an aircraft, first information associated with an accuracy of signals transmitted by a localizer. Aspects also include obtaining, using the aircraft, second information associated with an accuracy of signals transmitted by a glide slope station. Aspects also include transmitting the first information and the second information to a ground receiver for processing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/479,988 filed on Apr. 5, 2017, which claims priority to U.S.Provisional Application No. 62/319,667 filed on Apr. 7, 2016, thecontents of which are hereby incorporated herein in their entirety.

TECHNICAL FIELD

The present disclosure relates generally to the field of avionics, andmore specifically to devices, systems, and methods for transmittingflight check data for one or more navigational aid systems using amanned or unmanned aircraft.

BACKGROUND

Pilots generally rely on very high frequency (VHF) omnidirectional range(VOR) navigation systems, instrument landing systems (ILSs), and/ordistance measuring equipment (DME) to aid with navigation and landingwhen flying during periods of low visibility or inclement weather.Generally, a VOR system is implemented by dispersing VOR transmitterfacilities across a geographic area. VOR receivers, located on theaircraft, receive signals from VOR transmitters and help guide theaircraft through such geographic areas. The basic principle of operationof the VOR navigation system may include the VOR transmittertransmitting two signals at the same time. One VOR signal may betransmitted constantly in all directions, while another signal isrotatably transmitted about the VOR transmission facility. The airborneVOR receiver receives both signals, analyzes the phase differencebetween the two signals, and interprets the results as a radial to orfrom the VOR transmitter. Thus, the VOR navigation system allows a pilotto simply, accurately, and without ambiguity navigate from VORtransmitter facility to VOR transmitter facility. Each VOR transmissionfacility operates at a frequency that is different from the surroundingVOR transmitters. Therefore a pilot may tune the aircraft VOR receiverto the VOR transmission facility with respect to which navigation isdesired.

The ILS is a ground-based instrument approach system that providesaircraft with lateral guidance (e.g., from localizer antenna array) andvertical guidance (e.g., glide slope antenna array) while approachingand landing on a runway. In principle, an aircraft approaching a runwayis guided by ILS receivers in the aircraft that perform modulation depthcomparisons of signals transmitted by a localizer antenna array locatedat the end of the runway and by a glide slope antenna array located toone side of the runway touchdown zone.

Generally speaking, two signals are transmitted by the localizer fromco-located antennas within the array. One signal is modulated at a firstfrequency (e.g., 90 Hz), while the other signal is modulated at a secondfrequency (e.g., 150 Hz). Each of the co-located antennas transmits anarrow beam, one slightly to the left of the runway centerline, theother slightly to the right of the runway centerline. The localizerreceiver in the aircraft measures the difference in the depth ofmodulation (DDM) of the first signal (e.g., 90 Hz) and the second signal(e.g., 150 Hz). The depth of modulation for each of the modulatingfrequencies is 20 percent when the receiver is on the centerline. Thedifference between the two signals varies depending on the deviation ofthe approaching aircraft from the centerline. The pilot controls theaircraft so that a localizer indicator (e.g., cross hairs) in theaircraft remains centered on the display to provide lateral guidance.

Similarly, the glide slope (GS) antenna array transmits a first signalmodulated at a first frequency (e.g., 90 Hz) and a second signalmodulated at a second frequency (e.g., 150 Hz). The two GS signals aretransmitted from co-located antennas in the GS antenna array. The centerof the GS signal is arranged to define a glide path of a predeterminedslope (e.g., 3°) above the ground level for the approach of theaircraft. The pilot controls the aircraft so that a guide slopeindicator (e.g., cross hairs) remains centered on the display to providevertical guidance during landing.

In aviation, the basic objective for flight inspection of the variousnavigation aid systems has remained much the same for the last half acentury. For example, flight inspection services (FIS) are provided byan agency such as the Federal Aviation Administration (FAA), and provideairborne flight check of electronic signals-in-space from ground-basednavigational aid equipment that support aircraft departure, en-route,and arrival flight procedures. The flight check are conducted by a crewusing a fleet of specially-equipped flight inspection aircraft.

Currently, for example, there are various flight maneuvers that must beperformed by a flight inspection crew as part of a flight inspection ofthe various navigation aid systems. Each navigation aid system isinspected periodically, and requires an aircraft fleet that is expensiveto maintain, an inspection crew to fly and maintain the aircrafts, tenor more hours of flight time to accomplish, and appropriate weather toperform the flight maneuvers (e.g., not too windy and with goodvisibility).

Therefore, there exists an unmet need in the art for methods,apparatuses, and computer-readable media to perform the flight maneuversrequired to inspect navigational aid systems that reduces the expense ofmaintaining a fleet of aircraft, commissioning a crew, and which allowthe maneuvers to be performed under less than ideal weather conditions.

SUMMARY

Aspects of the present invention relate to methods, systems, andcomputer-readable media for performing a flight check of one or morenavigational aid systems. Aspects include obtaining, using an aircraft,first information associated with an accuracy of signals transmitted bya localizer. Aspects also include obtaining, using the aircraft, secondinformation associated with an accuracy of signals transmitted by aglide slope station. Aspects further include transmitting the firstinformation and the second information to a ground receiver forprocessing to increase an accuracy of the one or more navigational aidmeasurements.

Additional aspects may include receiving, from an aircraft, firstinformation associated with an accuracy of signals transmitted by alocalizer. Additional aspects may also include receiving, from theaircraft, second information associated with an accuracy of signalstransmitted by a glide slope station. Additional aspects may furtherinclude receiving location information associated with a position of theaircraft. Additional aspects may include determining the accuracy of thesignals transmitted by the localizer based on the first information andthe location information. Additional aspects may further includedetermining the accuracy of the signals transmitted by the glide slopestation based on the second information and the location information.

Additional advantages and novel features of these aspects will be setforth in part in the description that follows, and in part will becomemore apparent to those skilled in the art upon examination of thefollowing or upon learning by practice of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and constitute apart of this specification, illustrate one or more example aspects ofthe invention and, together with the detailed description, serve toexplain their principles and implementations.

FIG. 1 is a diagram illustrating one example of a system in accordancewith various aspects of the present disclosure.

FIG. 2 is a flow diagram illustrating an example method for performing aflight check of one or more navigational aid systems in accordance withvarious aspects of the present disclosure.

FIG. 3 is a flow diagram illustrating an example method for performing aflight check of one or more navigational aid systems in accordance withvarious aspects of the present disclosure.

FIG. 4 a system diagram illustrating various example hardware componentsand other features, for use in accordance with aspects of the presentdisclosure.

FIG. 5 is a diagram illustrating example aspects of a hardwareimplementation for a system employing a processing system in accordancewith aspects of the present disclosure.

FIG. 6 is a diagram illustrating example aspects of a hardwareimplementation for a system employing a processing system in accordancewith aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of a method of performing a flight check of navigationalaid systems using an unmanned aircraft will now be presented withreference to various methods, apparatuses, and media. These methods,apparatuses, and media will be described in the following detaileddescription and illustrated in the accompanying drawings by variousblocks, modules, components, circuits, steps, processes, algorithms,etc. (collectively referred to as “elements”). These elements may beimplemented using electronic hardware, computer software, or anycombination thereof. Whether such elements are implemented as hardwareor software depends upon the particular application and designconstraints imposed on the overall implementation.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented with a “processing system”that includes one or more processors. Examples of processors includemicroprocessors, microcontrollers, digital signal processors (DSPs),field programmable gate arrays (FPGAs), programmable logic devices(PLDs), state machines, gated logic, discrete hardware circuits,discrete radio frequency (RF) circuits, and other suitable hardwareconfigured to perform the various functionality described throughoutthis disclosure. One or more processors in the processing system mayexecute software. Software shall be construed broadly to includeinstructions, instruction sets, code, code segments, program code,programs, subprograms, software components, applications, softwareapplications, software packages, routines, subroutines, objects,executables, threads of execution, procedures, functions, etc., whetherreferred to as software, firmware, middleware, microcode, hardwaredescription language, or otherwise.

Accordingly, in one or more example embodiments, the functions describedmay be implemented in hardware, software, firmware, or any combinationthereof. If implemented in software, the functions may be stored on orencoded as one or more instructions or code on a computer-readablemedium or media. Computer-readable media includes computer storagemedia. Storage media may be any available media that is able to beaccessed by a computer. By way of example, and not limitation, suchcomputer-readable media can comprise a random-access memory (RAM), aread-only memory (ROM), an electrically erasable programmable ROM(EEPROM), compact disk ROM (CD-ROM) or other optical disk storage,magnetic disk storage or other magnetic storage devices, or any othermedium that may be used to carry or store desired program code in theform of instructions or data structures and that may be accessed by acomputer. Disk and disc, as used herein, include CD, laser disc, opticaldisc, digital versatile disc (DVD), and floppy disk, where disks usuallyreproduce data magnetically, while discs reproduce data optically withlasers. Combinations of the above should also be included within thescope of computer-readable media.

Aspects of a method, apparatus, and computer-readable medium presentedherein may be compatible with unmanned aircraft used in performing aflight check. For example, the method, apparatus, and computer-readablemedium may be compatible for performing a flight check with one or moreof the following: ILS, VOR, TACtical Air Navigation (TACAN), automaticdependent surveillance-broadcast (ADS-B), Marker Beacons (MB),Non-Directional Beacons (NDB), ground-based augmentation system (GBAS),Lighting Systems, and/or airport/aircraft communications, radar, and/orcharts. Although the description set forth below primarily refers to aflight check procedure for an ILS, VOR, and/or DME it should beunderstood that the methods, apparatuses, and computer-readable media ofthe present disclosure may be used with any of the foregoing navigationaid systems listed above without departing from the scope of the presentdisclosure.

Currently, there are various flight maneuvers that must be performed bya flight inspection crew as part of a flight inspection of the variousnavigation aid systems. Each navigation aid system is inspected on ascheduled basis, and requires an aircraft fleet that is expensive tomaintain, an inspection crew to fly and maintain the aircrafts, ten ormore hours of flight time to accomplish, and appropriate weather toperform the flight maneuvers (e.g., not too windy and with goodvisibility). In order to ensure the accuracy of navigation aid systemswhile reducing the cost and time of performing flight checks of thevarious navigation aid systems, the present disclosure provides a methodfor moving the storage and processes of data collected during a flightcheck from the aircraft to the ground.

The data collected while performing a flight check is referred to aschecklist data. Checklist data is defined in the US Standard FlightInspection Manual (FAA Order 8200.1, October 2005) as the minimum datato be verified during a flight check of a navigation system. Currentlythis data may be stored and processed using equipment in an aircraft.According to the present disclosure, the measured data from the flightcheck process may be sent to a ground processing system. This may reducethe weight and complexity in aircraft used to inspect navigational aidsystems, and potentially accelerate the data processing time. Theseaspects of the present disclosure may be useful for a small un-mannedflight check aircraft, but may also have benefits for manned aircraft.

FIG. 1 illustrates an overall system diagram of an example navigationaid testing system 100 for use in accordance with aspects of the presentdisclosure. The example system of FIG. 1 includes, for example, anunmanned aircraft 102 (e.g., shown on two example paths 110, 112), arunway 104, a localizer 106, a glide slope station 108, a GPS satellite114, a ground receiver 118, and a VOR station 122. In one aspect, themanned or unmanned aircraft 102 may be configured to learn a flight pathfor one or more airports depending on the navigational aid systems inuse at those airports. For example, the navigational aid systems mayinclude one or more of an ILS, VOR, DME, TACAN, ADS-B, MB, NDB, andGBAS. An ILS may include a localizer, sometimes a glideslope andsometimes a DME. In another aspect, the unmanned aircraft 102 may be abattery powered quadcopter or other drone.

In accordance with an example embodiment, the unmanned aircraft 102 isable to test navigation aid systems (e.g., such as an ILS) by crossingvia a first path 110 the ILS localizer course perpendicular to thenormal direction of flight at a certain distance (e.g., 10 miles) fromthe airport. In an aspect, the unmanned drone 102 may be kept at aconstant altitude (e.g., 2,000 ft) above the ground. During this check,first information associated with an accuracy of signals transmitted bythe localizer 106 may be obtained by measuring the width of thetransmitted localizer course (e.g., the two signals transmitted by thelocalizer 106) using the unmanned aircraft 102. The unmanned aircraft102 may transmit 120 a the first information associated with theaccuracy of the two localizer signals to a ground receiver 118 forprocessing. The ground receiver 118 may determine the accuracy of thetwo signals transmitted by the localizer 106 using the first informationreceived from the unmanned aircraft 102. In addition, the unmannedaircraft 102 may obtain positioning information 116 (e.g., one or moreof location information, speed information, heading information, oraltitude information) received from the GPS satellite 114 and transmitthe location information 120 a to the ground receiver 118. For example,the ground receiver 118 may determine the accuracy of the two signalstransmitted by the localizer 106 based on positioning information 124received from the GPS satellite 114. Alternatively, since the groundreceiver 118 knows a starting position of the flight check, a speed oftravel, and a direction of travel, the ground receiver 118 may determinethe accuracy of the two signals transmitted by the localizer 106 withoutreceiving location information (via transmissions 120a, 124) from theunmanned aircraft 102 and/or the GPS satellite 114. This process mayensure that a pilot will always receive correct localizer guidanceduring landing procedure.

In accordance with another example embodiment, the unmanned aircraft 102is able to test the navigation aid system (e.g., such as an ILS) byplacing the unmanned aircraft 102 on a level run along a second path 112at a constant altitude (e.g., 2,000 ft) above the ground flying alongthe glide slope course toward the airport. This level run on the secondpath 112 may be made to check the glide slope station 108 of thenavigational aid system and measure the actual width of the transmittedsignals from the glide slope station 108, which guides aircraft pilotthrough a descent to the runway. In an aspect, the unmanned aircraft 102may obtain second information associated with the accuracy of the twosignals transmitted by the glide slope station 108. During this check,second information associated with an accuracy of signals transmitted bythe glide slope station 108 may be obtained by measuring the width ofthe transmitted signals (e.g., the two signals transmitted by the glideslope station 108) using the unmanned aircraft 102. The secondinformation obtained by the unmanned aircraft 102 may be transmitted tothe ground receiver 118 for processing. In one aspect, the firstinformation and the second information may be transmitted 120 b togetherto the ground receiver 118. In another aspect, the first information andthe second information may be transmitted 120 b separately to the groundreceiver 118. In one example embodiment, the unmanned aircraft 102 mayreceive location information from the GPS satellite 114 that may be usedin determining an accuracy of the two signals transmitted by the glideslope station 108. The location information may be transmitted 120 b bythe unmanned aircraft 102 to the ground receiver 118 with the firstinformation and the second information. Alternatively, the locationinformation may be separately transmitted to the ground receiver 118.For example, the ground receiver 118 may determine the accuracy of thetwo signals transmitted by the glide slope station 108 based onpositioning information 116 received from one or more of the unmannedaircraft 102 and/or the GPS satellite 114. This process may ensure thata pilot will always receive correct glide slope guidance during alanding procedure.

Still further, in an example embodiment, the unmanned aircraft 102 isable to test the navigation aid system (e.g., such as a VOR, DME, orADS-B) by crossing via the first path 110 the VOR, DME, or ADS-Bperpendicular, parallel, or at an angle to the normal direction offlight at a certain distance (e.g., 10 miles) from the airport. Duringthis check, third information is transmitted 120 a that is associatedwith an accuracy of signals transmitted by the VOR station 122 (or DMEor ADS-B stations) may be obtained by receiving the two signals from theVOR station 122 and analyzing the phase difference between the twosignals. The unmanned aircraft 102 may interpret the results as a radialto or from the VOR station 122 (or DME or ADS-B stations). The unmannedaircraft 102 may transmit 120 a the third information associated withthe accuracy of the two VOR signals to the ground receiver 118 forprocessing. Alternatively, the third information may be transmitted 120a to the ground receiver 118 without being analyzed by the unmannedaircraft 102. In this alternatively example, the ground receiver 118 mayanalyze the phase difference between the two signals and interpret theresults as a radial to or from the VOR station 122 (or DME or ADS-Bstations). In addition, the unmanned aircraft 102 may obtain positioninginformation 116 (e.g., location information, speed information, headinginformation, or altitude information) received from the GPS satellite114 that is also transmitted 120 a to the ground receiver 118. Theground receiver 118 may determine accuracy of the two signalstransmitted by the VOR station 122 using the third information 120 andthe location information 116 received from the unmanned aircraft 102.Alternatively, since the ground receiver 118 may have receivedinformation for a starting position of the flight check, a speed oftravel, and a direction of travel, the ground receiver 118 may determinethe accuracy of the two signals transmitted by the VOR station based onthe third information without receiving location information from theunmanned aircraft 102 and/or the GPS satellite 114. This process mayensure that a pilot will always receive correct localizer guidanceduring landing procedure.

In accordance with a further example embodiment, the unmanned aircraft102 may fly the complete navigational aid system approach procedure tothe runway 104. This approach procedure may maneuver the unmannedaircraft 102 just above the runway so that both ends of the runway maybe visually marked by sensors on the unmanned aircraft 102. The visualmarkings may be way-points of a GBAS at the airport that the unmannedaircraft 102 transmits to the ground receiver 118. The ground receiver118 may be able to develop and/or validate an existing GBAS airportways-points using the information associated with the visual markingsreceived from one or more of the unmanned aircraft 102.

In this way, the unmanned aircraft 102 and the ground receiver 118 ofthe present disclosure is able to test navigational aid systems,localizer signals, glide slope signals, VOR, and DME coverage, whichwould otherwise not be possible using ordinary ground check equipmentand procedures. The ground receiver 118 of the present disclosure isalso able to develop and/or validate GBAS airport way-points with itsincluded precision GPS capabilities. When used in conjunction withlocation information, differential corrections of the localizer signals,glide slope signals, VOR signals, and/or DME signals using locationinformation may ensure enhanced accuracy during the flight checkprocedure. As a flight check tool, the unmanned aircraft 102 and theground receiver 118 is able to reduce the cost of the overallcommissioning of the runway equipment, the aircraft fleet, and theflight crew. By eliminating the need for humans to man the aircraft, theunmanned aircraft 102 and the ground receiver 118 of the presentdisclosure not only greatly reduces the cost of flight checks, butallows flight checks to be performed under situations previouslyconsidered cost prohibitive.

FIG. 2 is a flow diagram illustrating an example method 200 forperforming a flight check of one or more navigational aid systems inaccordance with various aspects of the present disclosure. The processdescribed in this flow diagram may be implemented and/or performed by anunmanned aircraft, such as the unmanned aircraft 102 illustrated inFIG. 1. For example, in FIG. 1, the unmanned aircraft 102 may include adrone, an unmanned aerial vehicle (UAV), and/or a battery operatedquadcopter. In an aspect, as shown in FIG. 1, the unmanned aircraft 102may be self-flying, meaning that the flight check may be performedwithout or with minimal human interaction. In an alternative aspect, asshown in FIG. 1, a user may remotely control the unmanned aircraft 102for at least a portion of the flight check. It should be understood thatthe operations indicated with dashed lines represent optional operationsfor various aspects of the disclosure.

At block 202, the unmanned aircraft may obtain first informationassociated with an accuracy of signals transmitted by a localizer. Forexample, referring to FIG. 1, first information associated with anaccuracy of signals transmitted by the localizer 106 may be obtained bymeasuring the width of the transmitted localizer course (e.g., the twosignals transmitted by the localizer 106) using the unmanned aircraft102.

At block 204, the unmanned aircraft may obtain second informationassociated with an accuracy of signals transmitted by a glide slopestation. For example, referring to FIG. 1, second information associatedwith an accuracy of signals transmitted by the glide slope station 108may be obtained by measuring the width of the transmitted signals (e.g.,the two signals transmitted by the glide slope station 108) using theunmanned aircraft 102.

At block 206, the unmanned aircraft may transmit the first informationand the second information to a ground receiver for processing. Forexample, referring to FIG. 1, the first information and the secondinformation obtained by the unmanned aircraft 102 may be transmitted tothe ground receiver 118 for processing. In one aspect, as shown inFIG.1, the first information and the second information may betransmitted together to the ground receiver 118. In another aspect, asshown in FIG. 1, the first information and the second information may betransmitted separately to the ground receiver 118.

At block 208, the unmanned aircraft may obtain location information. Forexample, referring to FIG. 1, the unmanned aircraft 102 may receivelocation information from the GPS satellite 114 that may be used indetermining an accuracy of the two signals transmitted by the glideslope station 108.

At block 210, the unmanned aircraft may transmit at least one oflocation information, speed information, heading information, oraltitude information. For example, referring to FIG. 1, the unmannedaircraft 102 may receive at least one of location information, speedinformation, heading information, or altitude information from the GPSsatellite 114 that may be used in determining an accuracy of the twosignals transmitted by the glide slope station 108. As shown in FIG. 1,the at least one of location information, speed information, headinginformation, or altitude information may be transmitted by the unmannedaircraft 102 to the ground receiver 118 with the first information andthe second information.

At block 212, the unmanned aircraft may obtain and transmit thirdinformation associated with an accuracy of signals transmitted by VORequipment to the ground receiver. For example, referring to FIG. 1,third information may be obtained by receiving the two signals from theVOR station 122 and analyzing the phase difference between the twosignals. As further shown in FIG. 1, the unmanned aircraft 102 mayinterpret the results as a radial to or from the VOR station 122. InFIG. 1, the unmanned aircraft 102 may transmit 120 a the thirdinformation associated with the accuracy of the two VOR signals to aground receiver 118 for processing.

At block 214, the unmanned aircraft may obtain measurements from leastone of a DME or ADS-B equipment and transmit information associated withthe measurements to the ground receiver. For example, referring to FIG.1, third information associated with an accuracy of signals transmittedby DME or ADS-B stations may be obtained by receiving the two signalsfrom the VOR station 122 and analyzing the phase difference between thetwo signals.

FIG. 3 is a flow diagram illustrating an example method 300 forperforming a flight check of one or more navigational aid systems inaccordance with various aspects of the present disclosure. The processdescribed in this flow diagram may be implemented and/or performed by aground receiver, such as the ground receiver 118 illustrated in FIG. 1.For example, in FIG. 1, the ground receiver 118 may include one or moreprocessors that analyze signals received from one or more of theunmanned aircraft 102 and/or the GPS satellite 114. It should beunderstood that the operations indicated with dashed lines in FIG. 3represent optional operations for various aspects of the disclosure.

At block 302, the ground receiver may receive first informationassociated with an accuracy of signals transmitted by a localizer. Forexample, referring to FIG. 1, first information associated with anaccuracy of signals transmitted by the localizer 106 may be obtained bymeasuring the width of the transmitted localizer course (e.g., the twosignals transmitted by the localizer 106) using the unmanned aircraft102. The first information and the second information obtained by theunmanned aircraft 102, as shown in FIG. 1, may be transmitted to theground receiver 118 for processing. In one aspect, as shown in FIG. 1,the first information and the second information are transmittedtogether to the ground receiver 118. In another aspect, as shown in FIG.1, the first information and the second information are transmittedseparately to the ground receiver 118.

At block 304, the ground receiver may receive, from the aircraft, secondinformation associated with an accuracy of signals transmitted by aglide slope station. For example, referring to FIG. 1, secondinformation associated with an accuracy of signals transmitted by theglide slope station 108 may be obtained by measuring the width of thetransmitted signals (e.g., the two signals transmitted by the glideslope station 108) using the unmanned aircraft 102. As further shown inFIG. 1, the first information and the second information obtained by theunmanned aircraft 102 may be transmitted to the ground receiver 118 forprocessing. In one aspect, as shown in FIG. 1, the first information andthe second information may be transmitted together to the groundreceiver 118. In another aspect, as shown in FIG. 1, the firstinformation and the second information may be transmitted separately tothe ground receiver 118.

At block 306, the ground receiver may receive at least one of locationinformation, speed information, heading information, or altitudeinformation associated with a position of the aircraft. For example,referring to FIG. 1, the unmanned aircraft 102 may receive at least oneof location information, speed information, heading information, oraltitude information from the GPS satellite 114 that may be used indetermining an accuracy of the two signals transmitted by the glideslope station 108. The at least one of location information, speedinformation, heading information, or altitude information may betransmitted 120 a by the unmanned aircraft 102 to the ground receiver118 with the first information and the second information, as shown inFIG. 1. Alternatively, the at least one of location information, speedinformation, heading information, or altitude information may beseparately transmitted to the ground receiver 118. The locationinformation 124 may be received at the ground receiver 118 from the GPSsatellite 114, as further shown in FIG. 1.

At block 308, the ground receiver may determine the accuracy of thesignals transmitted by the localizer based on the first information andat least one of location information, speed information, headinginformation, or altitude information. For example, referring to FIG. 1,ground receiver 118 may determine the accuracy of the two signalstransmitted by the localizer 106 based on positioning information 124received from the GPS satellite 114 positioning information 120 areceived from the GPS satellite 114.

At block 310, the ground receiver may determine the accuracy of thesignals transmitted by the glide slope station based on the secondinformation and the at least one of location information, speedinformation, heading information, or altitude information received fromthe aircraft. For example, referring to FIG. 1, the ground receiver 118may determine the accuracy of the two signals transmitted by the glideslope station 108 based on positioning information 116 received from oneor more of the unmanned aircraft 102 and/or the GPS satellite 114.

At block 312, the ground receiver may receive, from the aircraft, thirdinformation associated with an accuracy of signals transmitted by VORequipment. For example, referring to FIG. 1, third information may beobtained by the unmanned aircraft 102 by receiving the two signals fromthe VOR station 122 and analyzing the phase difference between the twosignals. As further shown in FIG. 1, the unmanned aircraft 102 mayinterpret the results as a radial to or from the VOR station 122. Asshown in FIG. 1, the unmanned aircraft 102 may transmit 120 a the thirdinformation associated with the accuracy of the two VOR signals to aground receiver 118 for processing. Alternatively, for example, as shownin FIG. 1, the unmanned aircraft 102 may transmit 120 a the thirdinformation to the ground receiver 118 without analyzing the phasedifference between the two signals and/or interpreting the results as aradial to or from the VOR station 122.

At block 314, the ground receiver may receive, from the aircraft, thirdinformation associated with at least one of a DME or ADS-B equipment.For example, referring to FIG. 1, third information associated with anaccuracy of signals transmitted by DME or ADS-B stations may bedetermined by receiving the two signals from the VOR station 122 andanalyzing the phase difference between the two signals. As further shownin FIG. 1, the unmanned aircraft 102 and/or ground receiver 118 mayinterpret the results as a radial to or from the DME or ADS-B stations.

At block 316, the ground receiver may determine an accuracy of the DMEor ADS-B equipment using the third information and the at least one oflocation information, speed information, heading information, oraltitude information received from the aircraft. For example, referringto FIG. 1, ground receiver 118 may determine accuracy of the two signalstransmitted by the DME or ADS-B stations using the third informationreceived via transmission 120 a and the at least one of locationinformation, speed information, heading information, or altitudeinformation 116 received from the unmanned aircraft 102.

FIG. 4 is an example system diagram of various hardware components andother features, for use in accordance with aspects presented herein. Theaspects may be implemented using hardware, software, or a combinationthereof and may be implemented in one or more computer systems or otherprocessing systems. In one example, the aspects may include one or morecomputer systems capable of carrying out the functionality describedherein, e.g., in connection with FIGS. 2 and 3. An example of such acomputer system 500, 600 is shown in FIGS. 5 and 6.

In FIG. 4, computer system 400 includes one or more processors, such asprocessor 404. For example, the processor 404 may be configured forsignal processing at an unmanned aircraft and/or ground receiver. Theprocessor 404 is connected to a communication infrastructure 406 (e.g.,a communications bus, cross-over bar, or network). Various softwareaspects are described in terms of this example computer system. Afterreading this description, it will become apparent to a person skilled inthe relevant art(s) how to implement the aspects presented herein usingother computer systems and/or architectures.

Computer system 400 may include a display interface 402 that forwardsgraphics, text, and other data from the communication infrastructure 406(or from a frame buffer not shown) for display on a display unit 430. Inan aspect, the display unit 430 may be included in an unmanned aircraft.In another aspect, the display unit 430 may be located in the groundreceiver and configured to display data and/or measurements obtainedusing the unmanned aircraft. Computer system 400 also includes a mainmemory 408, preferably random access memory (RAM), and may also includea secondary memory 410. The secondary memory 410 may include, forexample, a hard disk drive 412 and/or a removable storage drive 414,representing a floppy disk drive, a magnetic tape drive, an optical diskdrive, etc. The removable storage drive 414 reads from and/or writes toa removable storage unit 418 in a well-known manner Removable storageunit 418, represents a floppy disk, magnetic tape, optical disk, etc.,which is read by and written to removable storage drive 414. As will beappreciated, the removable storage unit 418 includes a computer usablestorage medium having stored therein computer software and/or data.

In alternative aspects, secondary memory 410 may include other similardevices for allowing computer programs or other instructions to beloaded into computer system 400. Such devices may include, for example,a removable storage unit 422 and an interface 420. Examples of such mayinclude a program cartridge and cartridge interface (such as that foundin video game devices), a removable memory chip (such as an erasableprogrammable read only memory (EPROM), or programmable read only memory(PROM)) and associated socket, and other removable storage units 422 andinterfaces 420, which allow software and data to be transferred from theremovable storage unit 422 to computer system 400.

Computer system 400 may also include a communications interface 424.Communications interface 424 allows software and data to be transferredbetween computer system 400 and external devices. Examples ofcommunications interface 424 may include a modem, a network interface(such as an Ethernet card), a communications port, a Personal ComputerMemory Card International Association (PCMCIA) slot and card, etc.Software and data transferred via communications interface 424 are inthe form of signals 428, which may be electronic, electromagnetic,optical or other signals capable of being received by communicationsinterface 424. These signals 428 are provided to communicationsinterface 424 via a communications path (e.g., channel) 426. This path426 carries signals 428 and may be implemented using wire or cable,fiber optics, a telephone line, a cellular link, wireless communicationslink, a radio frequency (RF) link and/or other communications channels.In this document, the terms “computer program medium” and “computerusable medium” are used to refer generally to media such as a removablestorage drive 480, a hard disk installed in hard disk drive 412, andsignals 428. These computer program products provide software to thecomputer system 400. Aspects presented herein may include such computerprogram products.

Computer programs (also referred to as computer control logic) arestored in main memory 408 and/or secondary memory 410. Computer programsmay also be received via communications interface 424. Such computerprograms, when executed, enable the computer system 400 to perform thefeatures presented herein, as discussed herein. In particular, thecomputer programs, when executed, enable the processor 410 to performthe features described supra with respect to FIGS. 1, 2, and 3.Accordingly, such computer programs represent controllers of thecomputer system 400.

In aspects implemented using software, the software may be stored in acomputer program product and loaded into computer system 400 usingremovable storage drive 414, hard drive 412, or communications interface420. The control logic (software), when executed by the processor 404,causes the processor 404 to perform the functions as described herein.In another example, aspects may be implemented primarily in hardwareusing, for example, hardware components, such as application specificintegrated circuits (ASICs). Implementation of the hardware statemachine so as to perform the functions described herein will be apparentto persons skilled in the relevant art(s).

FIG. 5 is a representative diagram illustrating an example hardwareimplementation for a system 500 employing a processing system 502. Theprocessing system 502 may be implemented with an architecture that linkstogether various circuits, including, for example, one or moreprocessors and/or components, represented by the processor 504, thecomponents 512, 514, 516, 518, 520 and the computer-readablemedium/memory 506.

The processing system 502 may be coupled to or connected with anunmanned aircraft that is in communication with a ground receiver.

The processing system 502 may include a processor 504 coupled to acomputer-readable medium/memory 506 via bus 524. The processor 504 maybe responsible for general processing, including the execution ofsoftware stored on the computer-readable medium/memory 506. Thesoftware, when executed by the processor 504, may cause the processingsystem 502 to perform various functions described supra for anyparticular apparatus and/or system. The computer-readable medium/memory506 may also be used for storing data that is manipulated by theprocessor 504 when executing software. The processing system may furtherinclude at least one of the components 512, 514, 516, 518, 520. Thecomponents may comprise software components running in the processor504, resident/stored in the computer readable medium/memory 506, one ormore hardware components coupled to the processor 504, or somecombination thereof. The processing system 502 may be a component of anunmanned aircraft 102, as illustrated in FIG. 1.

The system 500 may further include features for obtaining, using anaircraft, first information associated with an accuracy of signalstransmitted by a localizer, obtaining, using the aircraft, secondinformation associated with an accuracy of signals transmitted by aglide slope station, transmitting the first information and the secondinformation to a ground receiver for processing, obtaining locationinformation, transmitting the location information to the groundreceiver for processing, obtaining third information associated with anaccuracy of signals transmitted by VOR equipment, and obtaining andtransmitting fourth information associated with an accuracy of at leastone of DME or ADS-B equipment.

The aforementioned features may be carried out via one or more of theaforementioned components of the system 500 and/or the processing system502 configured to perform the functions recited by the aforementionedfeatures.

Thus, aspects may include a system for performing a method of flightcheck of one or more navigational aid systems, e.g., in connection withFIG. 2.

The system may include additional components that perform each of thefunctions of the method of the aforementioned flowchart of FIG. 2, orother algorithm. As such, each block in the aforementioned flowchart ofFIG. 2 may be performed by a component, and the system may include oneor more of those components. The components may include one or morehardware components specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

Thus, aspects may include a non-transitory computer-readable medium forperforming a flight check of one or more navigational aid systems, thenon-transitory computer-readable medium having control logic storedtherein for causing a computer to perform the aspects described inconnection with, e.g., FIG. 2.

In yet another example, aspects presented herein may be implementedusing a combination of both hardware and software.

FIG. 6 is a representative diagram illustrating an example hardwareimplementation for a system 600 employing a processing system 602. Theprocessing system 602 may be implemented with an architecture that linkstogether various circuits, including, for example, one or moreprocessors and/or components, represented by the processor 604, thecomponents 612, 614, 616, 618, 620 and the computer-readablemedium/memory 606.

The processing system 602 may be coupled to or connected with a groundreceiver in communication with an unmanned aircraft.

The processing system 602 may include a processor 604 coupled to acomputer-readable medium/memory 606 via bus 624. The processor 604 maybe responsible for general processing, including the execution ofsoftware stored on the computer-readable medium/memory 606. Thesoftware, when executed by the processor 604, may cause the processingsystem 602 to perform various functions described supra for anyparticular apparatus and/or system. The computer-readable medium/memory606 may also be used for storing data that is manipulated by theprocessor 604 when executing software. The processing system may furtherinclude at least one of the components 612, 614, 616, 618, 620. Thecomponents may comprise software components running in the processor604, resident/stored in the computer readable medium/memory 606, one ormore hardware components coupled to the processor 604, or somecombination thereof. The processing system 602 may be a component of theground receiver 118, as illustrated in FIG. 1.

The system 600 may further include features for receiving, from anaircraft, first information associated with an accuracy of signalstransmitted by a localizer, receiving, from the aircraft, secondinformation associated with an accuracy of signals transmitted by aglide slope station, receiving, from the aircraft, location informationassociated with a position of the aircraft, determining the accuracy ofthe signals transmitted by the localizer based on the first informationand the location information received from the aircraft, determining theaccuracy of the signals transmitted by the glide slope station based onthe second information and the location information received from theaircraft, receiving, from the aircraft, third information associatedwith an accuracy of signals transmitted by VOR equipment, developing orvalidating one or more GBAS airport way-points using integrated GPSbased on at least one of the first information, the second information,or the location information, receiving, using the unmanned aircraft,fourth information associated with at least one of a DME or ADS-Bequipment, and determining an accuracy of the DME or ADS-B equipmentusing the fourth information and the location information received fromthe aircraft.

The aforementioned features may be carried out via one or more of theaforementioned components of the system 600 and/or the processing system602 configured to perform the functions recited by the aforementionedfeatures.

Thus, aspects may include a system for performing a flight check methodfor one or more navigational aid systems, e.g., in connection with FIG.3.

The system may include additional components that perform each of thefunctions of the method of the aforementioned flowchart of FIG. 3, orother algorithm. As such, each block in the aforementioned flowchart ofFIG. 3 may be performed by a component, and the system may include oneor more of those components. The components may include one or morehardware components specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

Thus, aspects may include a non-transitory computer-readable medium forperforming a flight check of one or more navigational aid systems, thenon-transitory computer-readable medium having control logic storedtherein for causing a computer to perform aspects of the methoddescribed in connection with, e.g., FIG. 3.

In yet another example, aspects presented herein may be implementedusing a combination of both hardware and software.

While the aspects described herein have been described in conjunctionwith the example aspects outlined above, various alternatives,modifications, variations, improvements, and/or substantial equivalents,whether known or that are or may be presently unforeseen, may becomeapparent to those having at least ordinary skill in the art.Accordingly, the example aspects, as set forth above, are intended to beillustrative, not limiting. Various changes may be made withoutdeparting from the spirit and scope of the disclosure. Therefore, thedisclosure is intended to embrace all known or later-developedalternatives, modifications, variations, improvements, and/orsubstantial equivalents.

Thus, the claims are not intended to be limited to the aspects shownherein, but are to be accorded the full scope consistent with thelanguage of the claims, wherein reference to an element in the singularis not intended to mean “one and only one” unless specifically sostated, but rather “one or more.” All structural and functionalequivalents to the elements of the various aspects described throughoutthis disclosure that are known or later come to be known to those ofordinary skill in the art are expressly incorporated herein by referenceand are intended to be encompassed by the claims. Moreover, nothingdisclosed herein is intended to be dedicated to the public regardless ofwhether such disclosure is explicitly recited in the claims. No claimelement is to be construed as a means plus function unless the elementis expressly recited using the phrase “means for.”

It is understood that the specific order or hierarchy of the processes/flowcharts disclosed is an illustration of example approaches. Basedupon design preferences, it is understood that the specific order orhierarchy in the processes/ flowcharts may be rearranged. Further, somefeatures/steps may be combined or omitted. The accompanying methodclaims present elements of the various features/steps in a sample order,and are not meant to be limited to the specific order or hierarchypresented.

Further, the word “example” is used herein to mean “serving as anexample, instance, or illustration.” Any aspect described herein as“example” is not necessarily to be construed as preferred oradvantageous over other aspects. Unless specifically stated otherwise,the term “some” refers to one or more. Combinations such as “at leastone of A, B, or C,” “at least one of A, B, and C,” and “A, B, C, or anycombination thereof” include any combination of A, B, and/or C, and mayinclude multiples of A, multiples of B, or multiples of C. Specifically,combinations such as “at least one of A, B, or C,” “at least one of A,B, and C,” and “A, B, C, or any combination thereof” may be A only, Bonly, C only, A and B, A and C, B and C, or A and B and C, where anysuch combinations may contain one or more member or members of A, B, orC. Nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims.

1. A method performed by an unmanned aerial vehicle (UAV), the methodcomprising: receiving signals transmitted by a navigational aid systemassociated with an aircraft runway; and determining informationindicating an accuracy of the received signals transmitted by thenavigational aid system.
 2. The method of claim 1, further comprising:transmitting the information indicating the accuracy of the receivedsignals through a wireless communication link to a ground-basedprocessing system for testing accuracy of the navigation aid system. 3.The method of claim 2, wherein receiving the signals transmitted by thenavigational aid system comprises receiving instrument landing system(ILS) signals from an ILS of the navigational aid system, anddetermining information indicating the accuracy of the received signalscomprises determining information indicating accuracy of the ILS signalsthat are received.
 4. The method of claim 3, wherein receiving the ILSsignals from the ILS of the navigational aid system comprises receivingthe ILS signals while controlling the UAV to fly on a flight path thatis perpendicular to an approach flight path of the aircraft runway. 5.The method of claim 3, wherein receiving the ILS signals from the ILS ofthe navigational aid system comprises receiving the ILS signals from alocalizer of the ILS of the navigational aid system.
 6. The method ofclaim 3, wherein the information indicating accuracy of the ILS signalsthat are received is determined based on a plurality of ILS signalsreceived at spaced apart locations along a flight path of the UAV; andwherein transmitting the information indicating the accuracy of thereceived signals comprises transmitting the information indicatingaccuracy of the ILS signals to the ground-based processing system. 7.The method of claim 5, wherein the information indicating accuracy ofthe ILS signals that are received is determined based on a plurality ofILS signals received at spaced apart locations along a flight path ofthe UAV within an approach flight path defined for aircraft to use whenapproaching to land on the aircraft runway.
 8. The method of claim 6,wherein receiving the ILS signals from the ILS of the navigational aidsystem comprises receiving the ILS signals from a glide slope station ofthe ILS of the navigational aid system.
 9. The method of claim 2,wherein receiving the signals transmitted by the navigational aid systemcomprises receiving a very high frequency (VHF) omnidirectional range(VOR) signals from a VOR station of a VOR navigation system.
 10. Themethod of claim 9, wherein determining information indicating theaccuracy of the VOR signals that are received comprises determininginformation indicating accuracy of VOR signals transmitted by the VORstation.
 11. The method of claim 9, the information indicating accuracyof the VOR signals that are received is determined based on a pluralityof VOR signals received at spaced apart locations along a flight path ofthe UAV relative to the VOR station.
 12. The method of claim 9, whereindetermining information indicating the accuracy of the VOR signals thatare received comprises determining information indicating accuracy ofVOR signals transmitted by the VOR station; and wherein transmitting theinformation indicating the accuracy of the received signals comprisestransmitting the information indicating accuracy of VOR signalstransmitted by the VOR station to the ground-based processing system.13. The method of claim 1, wherein the method further comprises:controlling the UAV to fly to a way-point location of a ground-basedaugmentation system (GBAS) of the aircraft runway; operating a sensor ofthe UAV to obtain a visual marking of the way-point of the GBAS of theaircraft runway; and transmitting the visual marking of the way-point ofthe GBAS of the aircraft runway and the information indicating anaccuracy of the received signals to the ground-based processing system.14. A method performed by a ground-based processing system associatedwith a navigational aid system of an aircraft runway, the methodcomprising: receiving information associated with an accuracy of signalsreceived by an unmanned aerial vehicle (UAV) from the navigational aidsystem; receiving information associated with flight operations of theUAV; determining an accuracy of the signals received by the UAV from thenavigational aid system based on the information associated with theaccuracy of the signals received by the UAV from the navigational aidsystem and the information associated with the flight operations of theUAV.
 15. The method of claim 14, wherein receiving the informationassociated with the accuracy of signals received by the UAV from thenavigational aid system comprises receiving the information associatedwith the accuracy of signals received by the UAV from the navigationalaid system through a wireless communication link from the UAV; andwherein receiving the information associated with flight operations ofthe UAV comprises receiving the information associated with flightoperations of the UAV through the wireless communication link from theUAV.
 16. The method of claim 14, wherein the information associated withthe accuracy of signals received by the UAV comprises informationassociated with the accuracy of signals transmitted by an instrumentlanding system (ILS) of the navigational aid system received by the UAV.17. The method of claim 16, wherein the information associated with theaccuracy of signals transmitted by the ILS comprises first informationassociated with accuracy of a localizer of the ILS and secondinformation associated with accuracy of a glide slope station of theILS.
 18. The method of claim 14, wherein the information associated withthe accuracy of signals received by the UAV comprises informationassociated with the accuracy of signals transmitted by a very highfrequency (VHF) omnidirectional range (VOR) navigation system.
 19. Themethod of claim 14, wherein the information associated with flightoperations of the UAV comprises at least one of location information,speed information, heading information, and altitude information as theUAV conducts flight operations associated with an approach flight pathof the aircraft runway.
 20. The method of claim 14, further comprising:receiving, from the UAV, visual information comprising a visual markingof a way-point of a ground-based augmentation system (GBAS) of theaircraft runway; and validating the waypoint of the GBAS based on thevisual information received from the UAV.
 21. A computer program productcomprising executable instructions stored on a non-transitorycomputer-readable medium that when executed by a processor of anunmanned aerial vehicle causes the processor to perform operationscomprising: receiving signals transmitted by a navigational aid systemassociated with an aircraft runway; and determining informationindicating an accuracy of the received signals transmitted by thenavigational aid system.
 22. A computer program product comprisingexecutable instructions stored on a non-transitory computer-readablemedium that when executed by a processor of a ground-based processingsystem associated with a navigation aid system of an aircraft runway,causes the processor to perform operations comprising: receivinginformation associated with an accuracy of signals received by anunmanned aerial vehicle (UAV) from the navigational aid system;receiving information associated with flight operations of the UAV;determining an accuracy of the signals received by the UAV from thenavigational aid system based on the information associated with theaccuracy of the signals received by the UAV from the navigational aidsystem and the information associated with the flight operations of theUAV.